Surgical instruments useful for endoscopic spinal procedures

Abstract

The present invention provides endoscopic instrumentation and surgical techniques especially useful for accessing and removing at least a portion of an intervertebral disc. Instrumentation includes tissue spreaders and cutting instruments. In particular, the tissue spreading instruments include instruments for spreading pre-sacral tissue such as fascia and for spreading adjacent vertebrae to facilitate access to the intervertebral disc. Endoscopic cutting instruments deliver a cutting blade in a sheathed position to the site of the disc nucleus followed by deployment to remove portions of the disc nucleus.

What is claimed is: 
     
       1. An endoscopic surgical instrument for spreading vertebrae comprising: a handle portion including a manually operable member;   an elongated endoscopic portion connected to said handle portion and extending distally therefrom, said endoscopic portion defining a longitudinal axis and having proximal and distal end portions;   a vertebrae spreading mechanism movably mounted with respect to said endoscopic portion, said vertebrae spreading mechanism including first and second vertebrae spreading arm members;   an actuation mechanism at least partially housed within said endoscopic portion and movable in response to movement of said manually operable member, said actuation mechanism including at least one camming element engageable with said first and second arm members to move said arm members from a closed to an open position, said first and second arm members deployable in a general transverse direction with respect to said longitudinal axis in response to movement of said manually operable member such that said first and second arm members remain in general parallel relation during deployment.   
     
     
       2. An endoscopic surgical instrument according to claim 1 wherein said actuation mechanism includes a rod member coaxially mounted within said endoscopic portion and reciprocally movable therewithin, said at least one camming element being positioned at a distal end of said rod member. 
     
     
       3. An endoscopic surgical instrument according to claim 2 wherein said first and second vertebrae spreading arm members include camming surfaces on an interior surface thereof, said camming surfaces configured to interfit with said at least one camming element. 
     
     
       4. An endoscopic surgical instrument according to claim 2 wherein said first and second vertebrae spreading arm members include substantially planar tissue contacting surfaces. 
     
     
       5. An endoscopic surgical instrument according to claim 4, wherein said tissue contacting surfaces of said first and second vertebrae spreading arm members extend in first and second planes respectively, said first and second planes being in general parallel relation to each other when the vertebrae spreading mechanism is in said closed position; wherein during deployment of said vertebrae spreading mechanism said first and second planes remain substantially mutually parallel between said closed and open positions.   
     
     
       6. An endoscopic surgical instrument according to claim 5 wherein said first and second arm members include camming surfaces on interior surfaces thereof, said camming surfaces configured to interfit with said at least one camming element for movement of said arm members between said closed and open positions. 
     
     
       7. An endoscopic surgical instrument according to claim 1 wherein said first and second vertebrae spreading arm members include curved tissue contacting surfaces. 
     
     
       8. An endoscopic surgical instrument according to claim 1 wherein said vertebrae spreading arm members include means for enhancing engagement with tissue. 
     
     
       9. An endoscopic surgical instrument according to claim 8 wherein said means for enhancing engagement is in the form of ridges, knurling, and serrations. 
     
     
       10. An endoscopic surgical instrument for spreading vertebrae, which comprises: an elongated frame defining a longitudinal axis and having proximal and distal end portions;   at least first and second vertebrae spreading arm members mounted to the distal end portion of the elongated frame, the first and second arm members moveable between a closed approximated position and an open spread position, and defining first and second outer tissue contacting surfaces, the first and second tissue contacting surfaces being in substantial parallel relation during movement of the first and second arm members between the closed and open positions and having structure to facilitate engagement with the vertebrae; and   camming means operatively engageable with the first and second arm members and actuable to move the spreading arm members between the closed and open positions.   
     
     
       11. The surgical instrument according to claim 10 wherein the camming means is actuable by a proximally positioned manually operable member. 
     
     
       12. The surgical instrument according to claim 11 including an actuating rod operatively connected to the manually operable member, the actuating rod moveable in response to corresponding movement of the manually operable member to actuate the camming means to thereby move the arm members between the closed and open positions. 
     
     
       13. The surgical instrument according to claim 12 wherein the manually operable member is adapted for rotational movement. 
     
     
       14. The surgical instrument according to claim 12 wherein the structure of the tissue contacting surfaces are in the form of ridges, knurling or serrations. 
     
     
       15. The surgical instrument according to claim 12 wherein the first and second tissue contacting surfaces are substantially planar. 
     
     
       16. The surgical instrument according to claim 15 wherein the first and second tissue contacting surfaces are in general parallel relation with the longitudinal axis of the frame during movement of the first and second arm members between the closed and open positions. 
     
     
       17. An endoscopic surgical instrument for distracting vertebrae, which comprises: an elongated frame defining a central longitudinal axis and having proximal and distal end portions;   at least two vertebrae spreading members mounted to the distal end portion of the elongated frame, at least one spreading member adapted for displacing movement relative to the other spreading member between a closed approximated position and an open spread position, the spreading members defining outer tissue contacting surfaces having structure to enhance engagement with the vertebrae, the tissue contacting surfaces being equidistally spaced with respect to the central longitudinal axis when in the open spread position;   a camming mechanism operatively engageable with the spreading members and having at least one camming element, the camming element moveable to move the spreading members between the closed and open positions; and   a proximally positioned manually operable member for actuating the camming mechanism.   
     
     
       18. The surgical instrument according to claim 17 wherein each vertebrae spreading member is adapted for movement in a general transverse direction relative to the central longitudinal axis between the closed and open positions. 
     
     
       19. The surgical instrument according to claim 18 wherein the tissue contacting surfaces are configured and dimensioned to be equidistally spaced with respect to the central longitudinal axis during movement between the closed and open positions. 
     
     
       20. The surgical instrument according to claim 19 wherein the tissue contacting surfaces are curved. 
     
     
       21. The surgical instrument according to claim 19 wherein the tissue contacting surfaces are planar. 
     
     
       22. An endoscopic surgical instrument for spreading vertebrae, which comprises: a handle portion having a manually operable actuating member;   an endoscopic portion connected to the handle portion and extending distally therefrom, the endoscopic portion including: an outer sleeve defining a longitudinal axis and having proximal and distal end portions; and   an actuating rod disposed within the outer sleeve and reciprocally movable therein in response to movement of the manually operable member;     at least a pair of vertebrae spreading members mounted to the distal end portion of the outer sleeve, the vertebrae spreading members extending in a general longitudinal direction and being in general parallel relation with the central longitudinal axis, the vertebrae spreading members adapted for relative movement to be displaced in a general transverse direction relative to the longitudinal axis while maintaining their parallel relation, the spreading members having outer contacting surfaces with structure to enhance engagement with the vertebrae; and   a camming mechanism including at least one camming element operatively engageable with the vertebrae spreading members and actuable in response to movement of the actuating rod to move the spreading members between a generally closed approximated position and an open spread position.   
     
     
       23. The surgical instrument according to claim 22 wherein the outer contacting surfaces of the spreading members are arcuate. 
     
     
       24. The surgical instrument according to claim 22 wherein the outer contacting surfaces of the spreading members are substantially planar.